1. Field of the Invention
The present invention relates to an organic light emitting device and a method for manufacturing the same.
2. Discussion of the Background
Recent trends toward lightweight and thin personal computers and television sets require lightweight and thin display devices. Thus, thin and light flat panel displays, such as a liquid crystal display (LCD), are being substituted for conventional cathode ray tubes (CRTs).
However, because the LCD is a passive display device, an additional back-light is added as a light source. Also, the LCD may have various problems such as a slow response time and a narrow viewing angle.
Among flat panel displays, an organic light emitting device (organic light emitting diode display, OLED display) has the most promise as a display device for solving these problems.
The organic light emitting device includes two electrodes and an organic light emitting layer interposed between the two electrodes. One of the electrodes injects holes into the light emitting layer and the other injects electrons. The injected electrons and holes combine to form excitons, which emit light as they discharge energy.
Emission layers for displaying red, green, and blue colors may be used to display full colors, and the same color emission layers may be arranged in rows of stripes.
Emission layers having the stripe structure may be formed using a shadow mask. Here, the shadow mask includes a plurality of openings having substantially the same size and shape as the emission layers, and an organic material is deposited through the openings such that the plurality of emission layers arranged in a row may be simultaneously formed.
However, because intervals between openings arranged in a row or column may be narrow, it may be difficult to minutely form the edge portions of the openings. Accordingly, when depositing organic material through the openings, a shadow effect, in which the organic material is not minutely deposited on the portions corresponding to the edges of the openings, may be generated. In this case, the area of the emission layers that are actually deposited is decreased such that the emitting area is decreased, thereby reducing the aperture ratio.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.